Self-priming pump



Se t. 28, 1954 B. c. BOECKELER SELF-PRIMING PUMP Filed Nov. 19, 1949 3Sheets-Sheet l FIGI FIG. 9

M R, '1 m m2 j M ATTORNEYS Sept. 28, 1954 B. c. BOECKELER SELF-PRIMINGPUMP File'd Nov. 19, 1949 3 Sheets-Sheet 3 INVENTOR ATTORNEYS 755mg,871M144, 7 /034 13mm Patented Sept. 28, 1954 2,690,129 SIELF-PRIMINGPUMP Benjamin Clark Boecke signor to The Hydroj ct Corporation,

ler, Trenton, Mich., as-

Trenton,

Mich., a corporation of Delaware Application November 19, 1949, SerialNo. 128,264

1 Claim. 1

This invention relates to rotary pumps and vacuum pumps and has for itsprincipal object a combination of rotary pump and vacuum pump providinga self-priming and/or gas eliminating rotary pump unit of exceptionalsimplicity. More particularly, my invention provides a selfprimingrotary pump unit with but a single moving part in a very compactstructure. .The term rotary pump is used herein to define the class ofpumps having a rotary member, namely, centrifugal, turbine, propellerand rotary pumps. The combination of my invention fills the need for asimple, efficient and trouble-free pump unit to pump various liquids,for example, water and chemicals, notably volatile liquid fuels such asgasoline or petrol and solvents. In addition to priming the rotary pump,the vacuum pump functions to remove gas from the liquid such as thevapors which are released in various organic liquids.

My invention comprises a rotary pump having an impeller, and a vacuumpump having a shell for confining a liquid annulus which is rotatable onthe impeller shaft and a jet pump, and a duct connecting the suctionside of the vacuum pump with the jet pump to remove air, gas'or vapor(hereinafter called gas) from the suction side of the pump and prime thepump. Advantageously, I mount the rotary member of the pump with itssuction and discharge chambers and the shell for confining the liquidannulus in a compact integral housing. The combination also includesmeans to maintain a uniform quantity of liquid in the annulus,preferably by duct means connected to the rotary pump, and means forremoving excess liquid from the annulus to maintain it at uniform depth.

One of the important features of my invention is the provision of a jetpump arranged to receive moving liquid from the liquid annulus to createthe vacuum and suck gas from the intake side of the rotary pump inpriming the pump and in eliminating at least a part of the gas from theliquid, and gas not so eliminated will be eliminated on the dischargeside of the pump.

These and other objects of the invention will be better understood afterconsidering the following discussion taken in conjunction with theaccompanying drawings, in which: I

Fig. 1 is an end view of a self-priming rotary pump unit of theinvention.

Fig. 2 is a plan view of the pump of Fig. 1 with parts broken away;

Fig. 3 is a side view of the unit of Fig. 1 with parts broken away;

Fig. 4 is a sectional view along line 4-4 of Fig. 1;

Fig. 5 is a sectional view along line 5-5 of Fig. 3;

Fig. 6 is an enlarged sectional view of a jet pump used in the pumpunit;

Figs. 7 and 8 are diagrammatic illustrations of a pump unit embodyingthe invention, as more particularly illustrated mechanically in Figs. 1to 6, and

Fig. 9 is a sectional view of another embodiment of pump unit of theinvention.

The pump unit illustrated in Figs. 1 to 5 comprises a housing Iconsisting of an end member 2 for enclosing the liquid discharge chamber3 of the centrifugal pump, an interior wall member 4 for enclosing thesuction chamber 5 of the centrifugal pump, and another wall member 6with an attached end plate 7 for enclosing the vacuum pump chamber 8.The drive shaft I0 is directly connected to the electric motor H andpasses centrally through the cover 1 and partition I 2. The shaftcarries on the inner end any suitable impeller 53 for the liquid beingpumped. The impeller ring it is in engagement with the partition I5 andprovides a central opening for directing the flow of liquid from thesuction chamber 5 to the impeller. The volute I6 for the impeller isattached to the partition l5 and is within the discharge chamber 3.Where the shaft passes through partition I2, it is sealed against thepassage of fluid by any suitable seal H such, for example, as one havinga spring, bellows, seal ring and collar. The seal is mounted over theshaft between the impeller and partition l2 and is held in sealingposition by the spacing ring I8. A similar seal '20 is mounted on theshaft where it passes through the cover I. Seal I! prevents the flow offluid between suction chamber 5 and the vacuum pump chamber 8, whileseal 20 prevents the flow of fluid between vacuum chamber 8 and theoutside.

An annular shell 22 is mounted on and keyed to the shaft l0 and, ofcourse, rotates with the impeller. The shell comprises a flat disc 23with radially disposed vanes 24 and a short cylindrical portion 25 fromwhich extends inwardly a radially disposed wall 26 which has asufliciently large central opening to provide for the entrance of thehub 27 of the cover I. The shell is accordingly enclosed within thechamber 8.

The suction chamber 5 has an inlet port to which the pipe 28 for thesupply of the liquid to be pumped is connected. The discharge chamber 3has a discharge port to which the pipe 29 for the discharge of liquid isconnected.

The jet pump 30 for priming the centrifugal pump is permanentlyconnected in a fixed position to the hub 21 by a tubular extension 3| inwhich isformed the duct a which leads to the low pressure. zone of thejet pump. Duct a enters the hub and then passes upwardly through thecover I (Fig. 1) to a space or enlargement 32 (Figs. v3 and 5) in memberfrom which the capillary 33 connects through partition l2 to the suctionchamber and the jet pump is accordingly connected to evacuate chamber 5in priming the centrifugal pump.

With reference to Figs. 2and 3, it will be seen that the capillary 33passes from the space 32 through the partition and into a space informedin the casting, portion 4 of the housing, which has a'bore holetherethrough for :the continuance of duct (1 into chamber 5. Theoutsideof the bore hole is closed with plug .34. Space 34 may be filled withwire mesh, and capillary 33 is of such a size, say, from 0.030 to 0.065inch in diameter, as to restrict the flow of liquid while passingsuiiicient gas to effect rapid priming.

I prefer to employ a-jet pump as particularly described andclaimed in mycopending application serial Number 128,265, filed November 19, 1949,now Patent No. 2,632,597 issued March 24, 1953. Such a jet pump has thecharacteristic feature of removing up to 2.2 volumes of gas for eachvolume of liquid passingthrough the device and to pull exceptionally lowvacuums.

When the pump is at'rest, a body of liquid is trapped in the shell 22and when-the pump is in operation the liquid assumes the form of arotating annulus 35 (Fig. 5). The entrance 36 of the jet pump is locatedin the liquid annulus and the high velocity liquid flows through thedevice to the discharge outlet 3'! creating the vacuum in duct a. Inorder to prevent an excessive amount of liquid accumulating'in theannulus, the skimmer 3B is mounted in a fixed position on the hub 21 andis set to skim ofi the excess to maintain the required depth of annulus.Skimmer 38 is capable of developing such a pressure as to conveytheliquid into the discharge gas separating chamber (Figs. 7 and 8)which-is under pressure. The central opening of the skimmer connects toduct 1) which passes upwardly through the cover 1 (Figs. 1, 4 and 5) andoutside as a pipe which enters the discharge chamber 3. .It may alsoconnectto a waste line :or to the separating chamber as in Figs. '7 and8. Apart of duct b may be restricted to form a capillary of from 0.030to 0.065 inch in diameter to control the flow of liquid. These capillarysizes are suitable for pumps having capacities in the order of 20gallons per minute. Larger size pumps require larger capillaries. Duct cextendsfromthe discharge chamher 3 of the centrifugal pump through theupper portion of the housing into the cover I, thence downwardly to thecapillary 39 in the hub 21 and into the space within the shell. Theprimary purpose of duct cis to take off any gas collecting in chamber 3and also'to vent any air carried back through duct 1). As an incidentalfeature, it carries liquid from the discharge chamberto the liquidannulus. Inorder to dischargegases from the chamber 8, the vent d(Fig. 1) is formed inthe upper portion of the cover I. Some liquidunavoidably accumulates in thechamber 8 and this liquid is removedthrough duct e and re- -53.feet per second is obtained which turned tothe liquid annulus where it is desired to save the liquid.

The self-priming centrifugal pump of the invention is illustrateddiagrammatically in Figs. '7 and 8 and the operation of the pump will bemore readily understood with reference to those diagrams. With theelectric motor operated at such a speed as to drive the shell 22 at aperipheral velocity of around 54 feet per second, the effective head ofthe liquid would be around 44 feet. Some slippage of the liquid must betaken into consideration. With the motor turning at 1750 R. P. M. andwith the shell having an inside diameter of 7 inches, an annulusvelocity of about is capable of giving a'shut off vacuum of about 26inches of mercury, or an absolute pressure of some 4 inches.

After the liquid annulus has been established and a stream of the liquidis forced through the jet pump, gas is sucked through duct a from thesuction side of the centrifugal pump, chamber 5, and is dicharged:through the jet pump along with the liquid into shell 22. The gas maybe allowed to escape to the atmosphere through the vent duct d, as shownin Fig. l, or through the space around the shaft, as shown in Fig. 7, orin the case of gases which must be confined, sent to an adsorbing devicenot shown. After evacuation of the suction side of the centrifugal pumphas been achieved, the pump operates in the normal manner by sucking theliquid through pipe 25 and discharging it to the discharge gas andseparating chamber from which it is directed to the place of use. Someliquid as well as vapor accompanies the gas discharged through the duct(1 and it is accordingly necessary to provide makeup liquid to maintainthe operating liquid annulus. Duct 0 extends from the discharge gasseparating chamber, whichis equivalent to chamber 3 of the centrifugalpump, to the shell. The capillary 39 in duct 0 is of such a size, say,from 0.035 to 0.065 inehin diameter, that it will provide but aslightexcess of liquid over that required. In order to maintain theproper'thickness of liquid annulus, the skimmer 38 removes the excessand directs itthrough duct b to the discharge gas separating chamber.

Some liquid unavoidably enters the chamber 8 and if allowed toaccumulate would interfere with the operation of the shell. The vanes onthe shell, Fig. 4, imparts such a velocity to the liquid which collectsin the chamber that it is forced to flow through duct 6 and be returnedto the liquid annulus in the shell.

Figs. '7 and 8 illustrate an arrangement of apparatus comprising theself-priming centrifugal pump unit of the invention for advantageous usein connection with the pumping of gasoline or petrol from an undergroundstorage tank to a pipe or hose 45 which leads to a dispensing means. Thevacuum pump removes gas or vapors from the suction side of thecentrifugal pump for priming purposes and also removes vapors or othergases which may accompany the liquid and are therefore separated so thata gas-free liquid may be discharged from the dispensing means.

Fig. 9 illustrates a rotary pump and vacuum pump combination mounted inthe casing 50. The vacuum pump comprises the chamber 5|, rotatable shell52 which is mounted on the shaft 53, and jet pump 54. The jet pumpconnects through duct 55 to "the suction chamber 55 of the rotary gearpump. The skimmer 5'! regulates the thickness of liquid annulus anddischarges the excess liquid out of the pump through duct 58. Gear 59 iskeyed to shaft and drives gear 60. Both gears operate in pressurechamber 61 in the usual manner.

The vacuum pump operates ina manner similar to the vacuum pump ofFig. 1. The vacuum created by the jet pump 54 evacuates chamber 56 andliquid is sucked through the inlet 62 to prime the pump. The rotary pumpthen functions in the usual way and discharges the liquid under pressurethrough outlet 63. Duct 58 may be connected to outlet line 63.

I claim:

A self-priming pump unit comprising a rotatable liquid pump having adischarge chamber, a vacuum pump including a jet pump, a rotatable shellfor receiving liquid, the vacuum pump having an inlet positioned toreceive liquid from a rotating annulus of liquid caused by rotation ofsaid shell, means for conducting liquid entering said inlet to the jetpump, a gas inlet for the jet pump communicating at one side with thesuction side of the liquid pump and at its other side with the jet pumpat a position to have gas from the suction side of the liquid pump drawntherethrough when liquid is passing through the jet pump, thereby toevacuate the suction side of the liquid pump to cause liquid to flow tothe suction side of the liquid pump for priming the liquid pump, a ductconnecting the discharge chamber of the liquid pump with the spacewithin said shell, means in said duct to control the flow of liquid toprovide make-up liquid for the annulus formed within the shell, andmeans for rotating said shell.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,591,388 Jennings July 6, 1926 2,134,686 De Lancey Nov. 1,1938 2,153,360 Auger Apr. 4, 1939 2,166,530 Morgan July 18, 19392,260,600 Boeckeler Oct; 28, 1941 2,368,528 Edwards Jan. 30, 19452,461,865 Adams Feb. 15, 1949 FOREIGN PATENTS Number Country Date597,751 Great Britain Feb. 3, 1948

